Carrier stop and track hangar for power and free conveyors



Oct. 17, 1967 e. A. TORRANCE CARRIER STOP AND TRACK HANGAR FOR POWER AND FREE CONVEYORS 2 Sheets-Sheet 1 Filed March 23, 1965 a R ON 5 WM m A 2 l. N o D R O G W/ 4 4 o 2 4 Y J L,

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Filed March 23, 1965 CARRIER S'i'OP AND TRACK HANGAR FOR POWER AND FREE CONVEYORS A. TQRRANCE 271 2 Sheets-Sheet 2 INVENTOR. GORDON A. TORRANCE i Z jwxvz ATTORNEYS United States Patent M 3,347,171 CARRIER STOP AND TRACK HAN GAR FOR POWER AND FREE CONVEYORS Gordon A. Torrance, Taylor, Niich, assignor to Jervis B. Webb Company, a corporation of Michigan Filed Mar. 23, 1965, Ser. No. 442,033 8 Claims. (Cl. 104172) ABSTRACT OF THE DISCLOSURE Device for stopping a carrier of a power and free conveyor by a stop plate which depresses the carrier driving dog and is abutted by the carrier holdback dog. The stop plate is actuatable between blocking and nonblocking positions, being secured to an arm pivoted to hangar structure which rigidly interconnects the carrier and propelling member tracks of the conveyor.

This invention relates to an improved construction for a combination track hangar and carrier stop for use with conveyors of the power and free type.

Conveyors of this type usually include an upper track supporting an endless propelling member equipped with pushers, and a lower track supporting a carrier equipped with driving and holdback dogs projecting toward the upper track for engagement by a pusher. In conveyors of this type it is frequently desirable to arrest movement of a carrier at a station along the path of travel, and various forms of wayside stopping devices have been employed for this purpose.

The object of the present invention is to provide an improved and simplified device of this type which will arrest movement of a carrier at a precise location and which incorporates structure for positively defining the relative position between the continuously moving propelling member and pushers, the carrier and the stopping device so that there will be no possibility of interference between these parts when carrier movement is arrested by the device.

A carrier stopping device constructed in accordance with the invention includes hangar structure secured to the propelling member and carrier supporting tracks of a power and free conveyor and rigidly interconnecting the tracks at a fixed distance from each other; an arm pivotally mounted on the hangar structure for rocking movement about an axis extending parallel to the tracks, the arm including a stop plate secured thereto and extending transversely and intermediate the tracks; and actuating means for rocking the arm between a non-blocking position in which the stop plate is spaced from the paths of travel of a pusher and the driving and holdback dogs of a carrier, and a blocking position in which the stop plate extends across the carrier supporting track in the path of travel of the carrier driving dog and holdback dog and spaced from the path of travel of a pusher on the propelling member.

Preferably the hangar structure consists of a pair of hangar members or plates extending normal to the tracks in spaced relation longitudinally thereof; and the arm and actuating means are mounted between the pair of plates, resulting in a very rigid structure for defining and maintaining the relative position of all components of the propelling member and pushers, carrier and carrier dogs, and of the stopping device itself.

In the blocking position of the arm of the stopping device, the stop plate extends into the path of travel of a carrier driving dog which is moved to a non-driving position upon engagement with the stop plate, the stop plate being then engaged by the carrier holdback dog to arrest Patented Oct. 17, 1967 carrier movement. An anti-backup device maintains the carrier in this position in which the stop plate engages the holdback dog and overlies the driving dog to retain it in non-driving position; also the arrangement is preferably one in which the holdback dog projects toward a pusher of the propelling member a distance less than does the driving dog so that the holdback dog also clears the path of travel of moving pushers when in engagement with the stop plate.

Other features and advantages will appear from the following description of the representative embodiment disclosed in the accompanying drawings in which:

FIGURE 1 is a side elevation of the propelling member and carrier supporting tracks of a power and free conveyor with the stopping device installed thereon;

FIGURE 2 is a transverse sectional elevation taken as indicated by the line 2-2 of FIG. 1; and

FIGURE 3 is a sectional plan view taken as indicated by the line 3-3 of FIG. 2.

The conveyor illustrated includes an upper I-beam propelling member supporting track 10 from which a propelling member in the form of an endless chain 12 equipped with pushers 13 is supported by trolleys 14. A lower carrier supporting track 16, formed by a pair of opposed channel members 17, supports carriers 18. Each carrier is equipped with a driving dog 20 normally urged to an extended or driving position shown in broken line in FIG. 1, and with a holdback dog 22 which preferably extends towards a pusher 13 a distance less than does the driving dog 20 in the driving position thereof.

The device of the invention includes the combination of track hangar structure which as shown consists of a pair of plate-like, U-shaped hangar members 24 and 26 extending transversely of the upper and lower tracks 10 and 16 in spaced relation longitudinally thereof. These hangar members 24 and 26 are secured to and rigidly interconnect the upper and lower track members 10 and 17 at a fixed distance from each other. The plates 24 and 26 are also rigidly secured together by connecting members 27, 28 and 29.

An arm 30 is pivotally suspended between the plates 24- and 26 for rocking movement about an axis defined by a pivot pin 32, the arm including a T-shaped, transversely extending upper portion 34 connected to a sleeve 35 which engages the pin 32, and a portion 38 extending downwardly around the upper track 10. A stop plate 40 is rigidly secured to the lower end of the downwardly extending portion 38, this connection including a gusset brace 41.

Actuating means in the form of a fluid pressure cylinder 42 is supported on the plate connecting member 27 and the rod of the cylinder is attached by a pivot pin 44 to the upper portion of the arm 30. When actuated, the cylinder 42 rocks the arm 30 about the pivot 32 between the blocking position shown in which the stop plate 40 extends across the carrier supporting track 16 in the path of travel of a carrier driving dog 20 and holdback dog 22 and spaced from the path of travel of a pusher 13 of the propelling member; and, a non-blocking position in which the stop plate is spaced from the path of travel of a pusher 13 and the carrier dogs 20 and 22.

When the stop plate 40 is in blocking position, which is defined by engagement between the arm 30 and the plate connecting member 29, the driving dog 20 of an approaching carrier being propelled by a pusher 13 will engage the bevelled edge 46 of the stop plate and be moved to a lowered non-driving position as the carrier 18 advances. Carrier movement will be arrested by engagement between the edge of the stop plate 40 and the holdback dog 22 as shown in FIG. 1, and a fixed abutment 48 is provided adjacent the stop plate to aid in absorbing this impact. When the stop plate is engaged by the holdback dog, a portion of the stop plate also overlies and retains the driving dog in depressed, non-driving position.

A simple anti-backup device is employed to maintain an arrested carrier in proper relation with the stop plate 40. This device merely consists of an arm 50 pivotally supported from a bracket 52 mounted on the upper flange of one of the carrier supporting tracks 17 and depending into the path of carrier movement through a slot 54 cut in such flange. The arm is biased to this position defined by engagement between its lower surface and the flange of the track member 17; and thus returns to this position after being moved out of the way by the wheels of a passing carrier.

When the arm 30 and stop plate 40 are moved to nonblocking position by the actuating means 42, the carrier driving dog 20, which is biased to driving position in the usual manner, returns thereto and is engaged by the next advancing pusher 13.

In many instances stopping devices are used to control the movement of carriers in zone of a conveyor system, for example, to limit the number of carriers in one zone at one time. For this type of operation, the stopping de vice is preferably normally urged by suitable means to the blocking position of the stop plate 40, as by a compression spring 56 mounted between end 57 of the actuat ing device 42 and a plate 58 abutting the fitting 60. This provides a fail-safe feature in the event of a power failure or other malfunction which would prevent normal operation of the stopping device, and the stop plate 40 will be moved to blocking position by the spring. to protect the system from undesired carrier movement. Such blocking movement of the stop plate can take place at any time without resulting in a jamming condition because the stop plate operates only on the driving and holdback dogs and is too wide to fit between them.

While preferred embodiments have been described above in detail, it will be understood that numerous modifications might be restored to without departing from the scope of the invention as defined in the claims.

I claim:

1. A combination track hangar and carrier stopping device for a conveyor of the type having an upper track supporting an endless propelling member and a lower track supporting a carrier equipped with driving and holdback dogs projecting toward the upper track for engagement by a pusher on the propelling member, said device comprising:

(a) track hangar structure secured to and rigidly interconnecting the upper and lower tracks at a fixed distance from each other;

(b) an arm pivotally suspended on the track hangar structure for rocking movement about an axis extending parallel to the tracks and spaced from the lower track, the arm including a stop plate secured thereto and extending transversely and intermediate the upper and lower, tracks; and

(c) actuating means for rocking the arm between a non-blocking position in which the stop plate is spaced from the paths of travel of a pusher and the carrier dogs and a blocking position in which the stop plate extends across the lower track in the path of travel of the carrier dogs and spaced from the path of travel of a pusher for abutting engagement with a carrier holdback dog and simultaneous overlying engagement with a carrier driving dog.

2. A track hangar and carrier stopping device as claimed in claim 1 wherein the track hangar structure comprises a pair of hangar members extending normal to the upper and lower tracks in spaced relation longitudinally thereof, and wherein the arm is pivotallysuspended between the pair of hangar members.

3. A track hangar and. carrier stopping device as claimed in claim 2 wherein the actuating means for rocking the arm is mounted between the pair of hangar members.

4. A track hangar and carrier stopping device as claimed in claim 1 wherein the pivotal axis of the arm is located above and in approximate vertical alignment with the longitudinal center line of the upper track, the arm including portions extending transversely and down wardly around one side of the upper track and the said stop plate being secured to the lower end of the downwardly extending portion.

5. A track hangar and carrier stopping device as claimed in claim 1 further including a fixed abutment engageable by the. stop plate in the blocking position thereof to absorb the impact between a moving carrier and the stop plate.

6. A track hangar and carrier stopping device as claimed in claim 1 further including an anti-backup'arm pivotally supported on the lower track and normally biased to an operative position in which a portion thereof extends into the path of reverse travel of a carrier for maintaining the carrier driving dog in engagement with the stop plate when the stop plate is in blocking position.

7. A track hangar and carrier stopping device as claimed in claim 1 further including means normally urging the stop plate to the blocking position thereof.

8. A track hangar and carrier stopping device as claimed in claim 1 further including a bevelled edge on the stop plate engageable with the carrierdogs.

References Cited UNITED STATES PATENTS 2,994,283 8/1961 Merritt 104-162 3,020,855 2/1962 Perkins l04-250 3,229,645 l/1966 Dehne 104-172 ARTHUR L. LA POINT, Primary Examiner.

D. F. WORTH, Assistant Examiner. 

1. A COMBINATION TRACK HANGAR AND CARRIER STOPPING DEVICE FOR A CONVEYOR OF THE TYPE HAVING AN UPPER TRACK SUPPORTING AN ENDLESS PROPELLING MEMBER AND A LOWER TRACK SUPPORTING A CARRIER EQUIPPED WITH DRIVING AND HOLDBACK DOGS PROJECTING TOWARD THE UPPER TRACK FOR ENGAGEMENT BY A PUSHER ON THE PROPELLING MEMBER, SAID DEVICE COMPRISING: (A) A TRACK HANGER STRUCTURE SECURED TO AND RIGIDLY INTERCONNECTING THE UPPER AND LOWER TRACKS AT A FIXED DISTANCE FROM EACH OTHER; (B) AN ARM PIVOTALLY SUSPENDED ON THE TRACK HANGER STRUCTURE FOR ROCKING MOVEMENT ABOUT AN AXIS EXTENDING PARALLEL TO THE TRACKS AND SPACED FROM THE LOWER TRACK, THE ARM INCLUDING A STOP PLATE SECURED THERETO AND EXTENDING TRANSVERSELY AND INTERMEDIATE THE UPPER AND LOWER TRACKS; AND (C) ACTUATING MEANS FOR THE ARM BETWEEN A NON-BLOCKING POSITION IN WHICH THE STOP PLATE IS SPACED FROM THE PATHS OF TRAVEL OF A PUSHER AND THE CARRIER DOGS AN A BLOCKING POSITION IN WHICH THE STOP PLATE EXTENDS ACROSS THE LOWER TRACK IN THE PATH OF TRAVEL OF THE CARRIER DOGS AND SPACEDA FROM THE PATH OF TRAVEL OF A PUSHER FOR ABUTTING ENGAGEMENT WITH A CARRIER HOLDBACK DOG AND SIMULTANEOUS OVERLYING ENGAGEMENT WITH A CARRIER DRIVING DOG. 